Introduction: Exposure to heat can impact the clinical efficacy and/or safety of transdermal and topical drug products. Understanding these heat effects and designing meaningful in vitro and in viv...

Chronic wounds remain a significant public problem and the development of wound treatments has been a research focus for the past few decades. Despite advances in the products derived from endogenous substances involved in a wound healing process (e.g. growth factors, stem cells, and extracellular matrix), effective and safe wound therapeutics are still limited. There is an unmet need to develop new therapeutics. Various new pathways and targets have been identified and could become a molecular target in designing novel wound agents. Importantly, many existing drugs that target these newly identified pathways could be repositioned for wound therapy, which will facilitate fast translation of research findings to clinical applications. This review discusses the newly identified pathways/targets and their potential uses in the development of wound therapeutics. Some herbs and amphibian skins have been traditionally used for wound repairs and their active ingredients have been found to act in these new pathways. Hence, screening these natural products for novel wound therapeutics remains a viable approach. The outcomes of wound care using natural wound therapeutics could be improved if we can better understand their cellular and molecular mechanisms and fabricate them in appropriate formulations, such as using novel wound dressings and nano-engineered materials. Therefore, we also provide an update on the advances in the wound therapeutics from natural sources. Overall, this review offers new insights into novel wound therapeutics.

(1) Background: Cardiotonic steroids have been found to stimulate collagen synthesis and might be potential wound healing therapeutics. The objective of this study was to evaluate the feasibility of digitoxigenin and its topical formulation for wound healing; (2) Methods: In the in vitro study, the human dermal fibroblast cells were treated with digitoxigenin and collagen synthesis was assessed. In the in vivo study, digitoxigenin was applied to excisional full-thickness wounds in rats immediately after wounding and remained for three days, and wound open was evaluated over 10 days. A digitoxigenin formulation for topical administration was prepared, and the in vitro release and in vivo wound healing effect were investigated; (3) Results: The expression of procollagen in human dermal fibroblast was significantly increased with the exposure to 0.1 nM digitoxigenin. Topical application of digitoxigenin in olive oil or alginate solution for three days significantly decreased the wound open in rats. Similarly, topical administration of the developed digitoxigenin formulation for three days also significantly increased wound healing. No wound healing effects were observed at days 7 and 10 after wounding when digitoxigenin was not applied; and, (4) Conclusions: It was possible to deliver digitoxigenin using the developed formulation. However, the wound healing effect of digitoxigenin and its mechanisms need to be further investigated in future studies.